Patent GB-665097-A (GB)
Title: Improvements in or relating to the manufacture of brushes
IPC: A46D3/05
Filed: 1947-08-08
Abstract: 665,097. Twisted stem brushes; brush making apparatus; forms of bristle. OSBORN MANUFACTURING CO. Aug. 8, 1947 [Aug. 6, 1945], No. 22093/47. Addition to 657,024. Class 19 Apparatus for making brushes by the method described in the parent Specification and for carrying out modifications of such method comprises means for advancing a continuous layer of brush material, means for applying a pair of parallel opposed elongated retaining members to opposite sides of the layer at spaced intervals therealong, means for subjecting the portions of the members in contact with said layer to heavy external pressure so as to compress the layer laterally and compact the same, means for twisting the portions of said members lying beyond the layer to secure said members together and hold the layer tightly therebetween and means for severing the layer between each successive pair of members. The retaining members preferably comprise flat faced wires as in the parent Specification but the use of such members in the apparatus is not essential. In the apparatus shown schematically in Fig. 5 the layer of brush material B<SP>2</SP> is passed over a guide roll 11 and is advanced at intervals a fixed distance so as to present successive portions of the layer to the brush making operations. The wires 1 preferably forming parts of a doubled wire with flat opposed faces are placed transversely of the brush layer and are then compressed upon the layer by opposed relatively movable jaws 12, 12 located in alignment with rotatable jaws 13, 13. While the jaws 12, 12 are compressed together the jaws 13 are rotated so as to twist the wires up to the edge of the layer of brush material. The layer of brush material is advanced successively by a distance equal to the transverse width of the flat tuft B to be severed from the layer to form the finished brush and the means for advancing the layer may be located between the jaws 12 and the shear blades 14 by which the layer is severed to form the finished brush. In the machine shown in Figs. 6 to 9 a continuous layer of brush material B<SP>3</SP> is subdivided into parallel layers which are guided through tubes 20 past clamp jaws 21, 21 and 22, 22 which are designed to be alternately closed upon and so grip the layer of brush material. These jaws are operated by hydraulically actuated pistons 23 and 24 which are in turn controlled by a system of electric circuits and limit switches. Jaws 21, 21 are relatively stationary while jaws 22, 22 are mounted on a carriage 25 reciprocated on guides 25a by means of an hydraulically activated piston 26 the operations being correlated so that when jaws 21, 21 are in open position, jaws 22, 22 will be closed to grip the layer of brush material and piston 26 will be activated to move the carriage 25 forwardly. On completion of this movement the jaws 21, 21 will in turn be closed, jaws 22, 22 opened and at the same time piston 26 will be moved in the reverse direction to return the carriage to starting position. The extent of the forward movement is controlled electrically and is equal to the transverse width of the successive sections to be severed from the layer of brush material to form the individual brushes. Wire W (Fig. 9) which is to form the stems of the brushes is fed upwardly and contiguous to one edge of the layer of brush material just beyond the path of movement of the jaws 22, 22 and two opposed shear blades 35 and 36 are located at an adjustable distance below the layer, the blade 36 being operated by a piston 37 to cut off the upper section of the wire. The severed wire has its midpoint opposite the layer of brush material and two spaced apart forming dies 38 are adapted in conjunction with a stationary pin 39 to bend the wire to enfold the brush layer. The dies 38 are reciprocated by piston 40 whose operation is controlled conjointly with pistons 37 and 26. The doubled wire is then delivered by the next advance movement of the brush layer to clamp jaws 41 and 42 which are mounted for rotation. Between these jaws are located two vertically reciprocable dies 43 and 44 which are forced together by pistons 45 and 46 so as to press on the wires and thus compact the layer of brush material therebetween. The electric circuits and valve arrangements are such that while the dies 43 and 44 are forced together the pistons 37 and 40 are actuated to cause a fresh section of wire W to be severed and doubled on the portion of brush layer which is to form the next brush. When the dies 43 and 44 are closed the clamp jaws 41 are rotated to twist the stem wires up to the point where they are pressed between the dies and a double shear 51 is then operated to sever the layer of brush material. The dies 43, 44 are then caused to open and the shear 51 is at the same time withdrawn. A brush of the flat type is thus obtained by opening the jaws 41 and 42. To obtain a helically formed brush, Fig. 2 (not shown), the jaws 41 are further rotated to complete the twisting of the portion of the stem wires between which the brush layer was pressed by the dies 43, 44. The brush material may consist of crimped brush wire, crimped or straight nylon or other synthetic brush material, or cord. Instead of doubling a single wire as described the two wires may be otherwise secured, thus they may be tacked together by brazing or welding or twisted together at the appropriate point.